Catalytic hydrogenation of nonnitrogenous esters



Patented Feb. 23, 1932- UNITED-STATES PATENT orF-lcE ALPEONS O. J'AEGEB,OF MOUNT LEIOANON, PENNSYLVANIA, ASSIGNOB TO THE- COMPANY, OFPITTSBURGH, PENINSYLVANIA, A. CORPORATION 01 DELAWARE carnmzrrcnrimoennn'rron or nonm'raoennous ES'I'EBS No Drawing. Originalapplication filed February 25, 1928', Serial 116,256,917. Divided andthis application filed September 23, 1929. Serial 'N'o. 394,733.

The invention relates to the catalytichydrogenation of non-nitrogenousesters in the liquid or vapor phase, with or without pressure, atordinary or elevated temperatures.

According to the present invention nonnitrogenous organic compounds arehydrogenated in the presence of a new class of catalyst compositions,either in the liquid or the vapor phase, by means of reducing gases ofall kinds, ,-f6r example, hydrogen, gases containing hydrogen, gasescontaining car-- bon monoxide, -such as water gas with or without thepresence of ethylene, methane,

-- carbon dioxide, water vapors, nitrogen and the like. In fact any ofthe ordinary reducing gases may be used. Contactrmasses used in theresent invention contain base exchange odies or their derivatives inwhich at least one component is present in nonv exchangeable form orimbedded as a diluent.

The invention does not include contact masses containing, when freshlyprepared, base exchange bodies-in which the only catalytically activecomponent having specific activity is present in exchangeable form.

Under the term base exchange body are included all natural or artificialbodies which possess the properties of exchanging their bases for otherbases of salt solutions. The base exchanging roducts used in makingcatalytic compositlons of the present invention or as initial materialfor derivatives to be so used may possess high base exchanging power orin many cases may possess lower base exchanging power, since the,catalytic value of the final compositions is not primarily dependent onthe amount of base exchang ing powe'r present. In general the baseexchange bodies may be divided into three main categories:-Two-component and multi-component zeolites, i. e., base exchangebodies containing chemicallycombined silicon in their nucleus andnon-silicious base exchange bodies in which all of the silicon isreplaced by other suitable acidic or amphoteric metal oxides.Two-component zeolites arethe reaction products of two types of: initialcomponents, that is to say, metallates and silicates (using the termmetallate in a somewhat broader sense as will be defined further on inthe description) or metal salts and silicates. Frequently more than onemember of a type may enter into reaction, that is to say,

a silicate may react with more than one metallate or more than one metalsalt. The multi-component zeolites are the reaction products of at leastthree types of components,

that is to say, at least one silicate, 'at least one metallate, and atleast one metal salt.

The base exchange bodies, both zeolites and non-silicious base exchangebodies, may be associated with diluents preferably in the form of aphysically homogeneous structure,

as will be described below. Either diluted or undiluted base exchangebodies may be "resent in the contact masses used in the presentinvention, or then derivatives may be present, but it should beunderstood that Y wherever base exchange bodies are referred to bothdiluted and undiluted products are of base exchange bodies withcompounds con- 1 taining anions capable of reacting with the baseexchange bodies to form products which possess many of the properties ofsalts. A further class of derivatives are the acid leached base exchangebodies. When a base exchange body is subjected to leaching by acids,particularly dilute mineral acids, the exchangeable bases are firstgradually removed. The resulting products contain both. the more basicand the more acidic components of the non-exchangeable nucleus of thebase exchange body, with or without a portion of the exchangeable bases.As the leaching is carried on further, more and more of the relativelypositive components of the non-exchangeable nucleus are removed, and

it carried to completion the leached product contains only therelatively acid components of the non-exchangeable nucleus In the caseof zeolites the finial product from long continued leaching is a complexsilicic acid which 9 yscial 7 has man of the physical properties of theoriginal ase exchange body. In he description and claims the class of,base exchange bodies and their derivatives will be referred to by thegeneric term permutogenetic products.

Catalytically active components may be associated with diluted orundiluted permu togenetic bodies in three main forms as follows :-(l)They may be physically admixed with or impregnated into thepermutogenetic products. (2) They may be physically homogeneouslyincorporated into the permutogenetic products before the latter havebeen completel formed in the form of catalyticaL, ly active diluentbodies or in the form of diluents which have been impregnated withcatalytically active substances. (3) They may be chemically combinedwith or in the permutogenetic products in non-exchangeable form, that isto say, they may form a part of the non-exchangeable nucleus of the baseexchange bod present in the final contact mass or which 1s transformedinto the derivatives, or they may be chemically combined with the baseexchange bodies in the ance to high temperatures,

form of catalytically active anions which form with the base exchangebody salt-like bodies. Obviously of course the same or dif ferentcatalytically active components may be present in more than one of theabove described forms, and it is an advantage of the present inventionthat catalyticall active substances ma be chemicall com ined innon-exchangea 1e form or p bined with permutogenetic bo es in a. widevariety of forms, which gives a wide field of choice to the catalyticchemist. While the difierent permutogenetic products may vary widely intheir chemical characteristics, they all possess a similar physicalstructure which is characterized by more or less high porosity,frequently microporosity, and great resistand in the case of productswhich have not been acid leached to the point of removal ofcatalytically active components these components are distributedthroughout the framework of the products in atomic or moleculardispersion, as will be described in-greater detail below, and thischemical homogeneity is one of the important advantages of some of thecontact masses of the present invention.

While two of the methods of combination of the catalytically activesubstances may be efiected with undiluted as well as dilutedpermutogenetic products, it has been found that for 'most reactionshomogeneously diluted permutogenetic contact masses are of advantage,particularly where the diluents are of a physical nature such as toexert a desired influence on a catalytic activity of the contact masses,as when, for example, diluents are rich in silica, which has been foundto have an activating power,'or where the diluents by sically comreasonof high porosity, capillarity, or surface energy may be considered asphysical catalysts or activators.

Base exchange bodies used in contact masses of the resent inventionbehave as if they were pro ucts of extremely high molec ular weight forcatalytically active components can be introduced into thenon-exchangeable nucleus in practically any desirable proportions andthe ordinary law of chemical combining proportions, which in compoundsof low molecular weight restricts the proportions in which componentscan be incorporated chemically, appears to be without force, which makesit reasonable to assume that the molecular weight is so high as tocompletely mask the effect of the law. It is of coursevpossible that thebase exchange bodies, or some of them, may be solid solutions of aplurality of related compounds of lower molecular weight. It has notbeen possiblehitherto to definitely settle this question, as baseexchange bodies are not readily capable of structural chemical analysis.The present invention is of course not limited to any theory, butirrespective of the underlying reasons the fact that catalyticallyactive components may be chemically introduced in any desiredproportions is of enormous importance to the catalytic chemist and giveshim the power to produce an almost'unlimited number of finely andgradually toned catalysts or contact masses for the various reductionsand hydrogenations of organic nitrogen compounds. In all cases thecontact masses produced are highly'effective by reason of the desirablephysical structure of the permutogenetic products contained therein andthe wide limits of homogeneous dilution of catalytically activemolecules or atoms with resulting uniformity and smoothness of action,which is of great importance, particularly for some relatively sensitivehydrogenations included within the scope of the present invention.

In addition to the important characteristics with which permutogeneticproducts endow the contact masses of the present invention-it has beenfound that for many of the reactions coming within the scope of thepresent invention it is desirable to stabilize the contact masses, andthis may be effected by associating with the permutogenetic products orincorporating or forming therein compounds of the alkali forming metals,that is to say, alkali metals, the alkaline earth metals, and thestrongly basic earth metals. These compounds appear to slow up or smoothout the catalytic reaction, and will be referred to throughout thisspecification as stabilizers. While for some reactions strongly alkalinestabilizers are not harmful, it has been found that for'many reactionsit is important to provide non-alkaline stabilizers, such as forexample, the salts or compounds or alkali forming metals which do notpossess an alkaline reaction. I It is a great advantage of the presentinvention that in the normal formation of base exchange bodies alkaliforming metal oxides are present as exchangeable Without acid treatmentor treated with acid, they form stabilizers which are combined in orassociated with the resulting permutogenetic products in an extremelyfine state of division in which the stabilizers are peculiarly active.Thus base exchange bodies containing alkali forming metal exchan eablebases may be considered as complex stabilizers.

In addition to the use of stabilizers which are important in a largenumber of hydrogenations included in the scope of the present invention,it has been found that the stabiliz er action and the overall efiiciencyof the contact masses can in many cases be greatly increased or enhancedwith the association therewith or chemical combination therein ofelements or radicals or groups which are catalytically active but do notpossess specific catalytic activity for the particular reaction to becarried out. Thus for example in the case of a hydrogenation reaction,certain catalysts which at the temperatures used in the reaction behaveas dehydrogenation catalysts may be added to enhance and tone thecatalytic activity of the catalysts or the operation of the stabilizers.Similarly in some. cases oxidation catalysts, such as those containingmetal elements of the fifth and sixth groups of the periodic system maygreatly improve the effectiveness of'the contact mass used, especiallywhere it is desirable to produce intermediate products which in somecases are relatively unstable. Some other reduction reactions involvethe splitting off of water or in some cases the splitting off of carbondioxide, and may also involve molecular condensations; In such reactionsit is very desirable to incorporate catalysts or catalytic componentswhich are not specific reduction catalysts but which may favordehydration, splitting ofi of carbon dioxide or condensation. Suchcatalysts or catalytic components which are not specific catalysts forthe reaction in which they are being used under the reaction conditionsobtaining will be referred to throughout the specification as stabilizerpromoters, as they ap ear to enhance the toning effect which can eachieved by stabilizers. The use of this expression should, however, inno sense be taken tolimit the invention to a particular theory of actionof these non-specific catalysts and in fact in some cases stabilizerpromoters may be present where there are no stabilizers.

The tremendous range of chemical groups which may be combined in or withor incorporated in permutogenetic products permits a wide choice ofstabilizer promoters as well bases, and whether used however, reason tobelieve as specific catalysts and permits their association with thecontact masses in an extremely homogeneous and catalytically efficientform. Thus many base exchange bodies or their derivatives may beconsidered as complex catalysts, stabilizers and stabilizer promoters,as all of these elements may be present in the same chemical compoundand sharing the advantages flowing from its'desirable physical structureand chemical properties. Of course both stabilizer and stabilizerpromoters may be mixed partly or wholly with prmutogenetic products anda single stabilizer or single stabilizer promoter may be present partlyin physical admixture and partly in chemical combination, as will beclear to the skilled base exchange chemist.

The base exchange bodies which form the important components or initialmaterial for derivatives in contact masses of the present invention maybe prepared in any of the well known methods. Thus for example,twocomponent zeolites may be prepared by wet methods, in which themetallate components or metal salt components, part or all of which maybe catalytically active, are caused 'to react with soluble silicates toform zeolites of alumino silicate or aluminum double silicate types, orthe components may be fused, preferably in the presence of fluxes. Itshould be understood that under the term metallate is included not onlythe alkaline solutions of amphoteric metal oxides or hydroxides but alsoalkali forming metal salts of metal acids, such as the oxyacids ofmetals of the fifth and sixth groups, which in at least one stage ofoxidation are not strictly speaking 'amphoteric, but which products arecapable of reacting with silicates to form zeolites, or with othercomponents to form non-silicious base exchange bodies. Throughout thespecification this somewhat more general definition of metallates willbe strictly adhered to. In the formation of two-component zeolites bywet methods, the final reaction product must be alkaline to litmus, andfor products of high baseexchanging power it should be neutral oralkaline to phenolphthalein. For the purpose of producing base exchangebodies to be used in-the preparation ofcontact masses of the presentinvention it is sometimes unnecessary to provide high base exchangingpower, and for many purposes zeolites formed under conditions resultingin a final reaction which is acid to phenolphthalein but alkalinetolitmus are of advantage. It is not definitely known whether productsproduced under such circumstances are homogeneous chemical compounds,although inmany ways they behave as such. There is,

that'in some cases at least mixtures of base exchanging and 'nonbaseexchanging polysilicates may be pro- 7 duced. For the purpose ofthepresent specifi- A n will be considered as a base cation a product highexchange product if it has any base exchange power at all.

It is desirable for many purposes and particularly where two-componentzeolites of base exchanging power are needed to add the relatively acidcomponents, for example, metal salts in the case of aluminum doublesilicate type of silicates, to the relativelymore alkaline componentssuch as for example soluble silicates. By these means a continuousalkalinity is insured, and this method may be considered as thepreferred method in most cases, but the opposite procedure isadvantageous for certain contact masses and is included in theinvention.

Multi-component zeolites may be prepared by any of the foregoing methodsusing at least three types of components, that is to say, at least onemetallate. at least one metal salt and at least one soluble silicate. Inthe case of multi-component zeolites, as in the case of two-componentzeolites, the conditions of alkalinity should be observed, and for manypurposes it is advantageous to add the relatively acid components to therelatively alkaline components, in order to insure continuous alkalinereaction. The multi-component zeolites produced vary in their nature,dependent on the proportion of the different reacting components. Thuswhere the metallates and silicates predominate over the metal salts theresulting products resemble the alumino silicate type of two-componentzeolites. If the metal salts and silicates predominate over themetallates the products resemble the aluminum double silicate type oftwo-component zeolites. and finally if the metallates and metal saltspredominate over the silicates the resulting product resembles more orless non-silicious base exchange bodies. It will be clear that there isno sharp defining line between the three types of multicomponentzeolites, and one shades into the other as the proportions of thedifferent com-.

ponents vary. It is an advantage of the multi-component zeolites overthe two-component zeolites that the choice of catalytically activecomponents is wider, as some catalytically active elements or groups canonly be incorporated in the form of metallates and others only in theform of metal salts. In a multi-component zeolite each catalyticallyactive group can be incorporated in the form in which it is bestavailable.

Non-silicious base exchange bodies areproduced by the general methodsdescribed above, but instead of bringing about reactions betweensilicates and other metal oxide components, two or more oxymetalcomounds are caused to react, in general, at east one will be ametallate and at least one a metal salt, or in some cases it is possibleto bring about action between two' difi'er'ent metallates in which onenegative radical is more acidic the. the other. It is possible toproduce non-silicious base exchange bodies in which a plurality of metaloxides are present. It is also possible to produce non-silicious baseexchange bodies in which a single metal is present. Thus for example,some metals may be sufiiciently amphoteric in character to form bothmetallates and metal salts which are capable of reacting with each otherto produce base exchange bodies.

A special method of producing non-silicious base exchange bodiesconsists in the gradual neutralization of strongly alkaline salts of theoxyacids of metal elements of the fifth and sixth groups of the periodictable in stages of oxidation ciently amphoteric. The neutralization ofother strongly alkaline metallates may also bring about formation ofnon-silicious base exchange bodies. The converse method, wherebynon-alkaline salts of suitable metals are gradually treated with alkaliuntil the reaction is sufiiciently alkaline to permit the formation ofbase exchange bodies, may also be used.

Many metals are capable of entering into the base exchange formationonly in certain stages of oxidation, and it is sometimes necessary tointroduce such metals in a stage of oxidation difierent from thatdesired in the final base exchange body, the change of stage ofoxidation being preferably effected during the formation of the baseexchange body. Certain other elements may be incorporated in the form ofcomplex compounds of the most various types, such as for example,ammonia complexes and the like.

In addition to the artificial base exchange bodies briefly describedabove, natural base exchange bodies. such as nepheline, leucite,felspar, and the like, may be used.

The most important contact masses for many reactions containpermutogenetic products in which preferably the diluents arehomogeneously incorporated into the base exchange bodies beforeformation of the latter, or at least before the base exchange body hasset after formation. Many diluents. both inert, stabilizing, activating,catalytically active. or having stabilizer promoter effects, can beused. A few of the diluents will be briefly enumerated :-kieselguhrs ofall kinds, particularly natural or treated celite earth. siliciouspowders of various types, powdered permutogen'etic products, natural orartificial powders of rocks, stones, tufis, trass, lava, and similarlyvolcanic products which are frequently highly porous, greensand,glauconite or it's acid leached derlvative glaucosil, pulverized slagwool. cements, sand, silica gel, pulverized earthenware, fullers earth,talc, glass powder. pumice meal, asbestos, graphite. activated carbon,quartz meal, various pulverized mlnerals rich in quartz, metal powdersand metal alloy powders, salts of oxymetal acids such as 1 in which theyare sufiiticularly copper salts of thefabove, silicates,

such as copper silicate, iron silicate, nickel silicate, cobaltsilicate, aluminum silicate, titanium silicate, minerals or ores,especially those rich in copper, etc. Finely divided diluents are ofgreat advantage, especially when the average particle size is less than60 microns, in which case the diluents' possess high surface energy,which increases the ad sorptive and hbsorptive capacity of the contactmass, the diffusion speed and porosity. These finely divided diluentsmay be'considered as physical catalysts or activators. Di lutedpermutogenetic bodies may also be finely divided and used as part orallof the diluents of other base exchange bodies.

The following nine methods are the most efl'ective for the introductionof diluents, but any other suitable methods can be used.

(1) The diluents may-be mixed with one or more liquid components of thebase exchange bodies to be formed when the latter are pre ared by wetmethods.

I (2) omponents, either catalytically active, stabilizer promoters,orothers, maybe precipitated or impregnated into diluent bodies which arethen incorporated into the base exchange bodies by any suitable methodsof incorporation.

(3) Diluents may be mixed with base exchange bodies while the latter arestill 1n the form of gels, by kneading or stirring, in which case thebase exchange gel behaves as an adhesive. The homogeneity and uniformityof the distribution of the diluents is of course not so great by thismethod as by method (1) Y but for many catalytic hydrogenations ofnon-nitrogenous organic compounds extreme uniformity is not essential.

(4) Diluents may be formed during the formation of base exchange bodiesby m1xing suitable compounds with the components of the base exchangebodies so that the diluent particles are precipitated dur ng formation.Protective colloids may be added to prevent coagulation of the diluentparticles before the base exchange bodies have become sufiiciently set.

(5) Compounds may be added which'react with certain of the base exchangebody forming components to produce diluents for 1nstance'salts ofthemetal acids of the fifth and sixth groups may be addedin sufiicientexcess so that they react with components of the base exchange body toform insoluble diluents, as for example with heavy metal oxldes. t (6)'Preformed base exchange bodies, d1-

luted or undiluted, artificial or natural, ,can"

be impregnated with true orcolloidal solutions of catalyticallyeffective components and then dried. (7) A preformed baseexchange body,d1-

luted or undiluted, may be impregnated with a plurality of solutionswhich we therein to preci itate any desired diluents.

(8) oluble diluent compounds may be added to the components forming abase exchange body, which after formation retains the compounds insolution and is dried without washing or is treated to precipitate thecompounds.

(9) Natural base exchange bodies or artificial base exchange bodies,diluted or undiluted, or their derivatives, may be impregnated withsolutions of the desired compounds, which are then precipitated by meansof reactive gases.

The. nucleus or non-exchangeable portion of the molecules of the baseexchange bodies is ordinaril considered to consist of two types of oxies, namely,'relatively basic metal which are capable of forming thebBSlC POT- tion' of the nucleus are those of the following metals:copper, silver, gold, bismuth, beryllium, zinc, cadmium, boron,aluminum, some rare earths, titanium, zirconium, tin, lead,

thorium, niobium, antimony, tantalum, chromlum, molybdenum, tungsten,uranium, vanadium, manganese, iron, nickel, cobalt, platinum, palladium.Compounds of these elements may be introduced singly or in mlxtures,inany desired proportions, and may be in the form of simple or complexions;

It should be. understood that some of the elements in certain stagesofoxidation may be introdubed either as metallates or metal salts.Others may be introduced in only one form, and stillothers may beintroduced in a stage of oxidation other than. that desired in the finalbase exchange body or in the form of complex compounds. Among thecomplex ionogens are ammonia, hydrocyanic acid, oxalic acld, formlcacld, tartaric acid, citric acid,'glycerine, and the like.

Many of the metals are specific catalysts,

others. are stabilizers, and still others are genation of the particularorganic compound for which the contact mass is to be used.

Examples of components formin the relatively acid portion of the baseexc ange nu- -.solub1e in alkali, and

nese, caesium, potassium,

tium, cadnuum, barium,

. nents present in non-exchangeable formeit silidates, which are alkalimetal salts of hosphorus, ni-

cleus are alkali metal acids, such as those of boron,

trogen, tin, titanium,.vana 'um, tungsten,

chromium, niobium, tantalum, uranium, antimony, man ganeseioetc.

The exchangea e bases of the base exchange bodies may be substituted bybase and the elements which can be inor in admixture by base exfollowing:-copper, silver, beryllium, calcium, mangasodium, zinc, stronlead,aluminum, scandium, titanium, zirconium, tin, antimon thorium, vanadium,lithium, rubidium, th ium, bismuth, chromium, uranium, manganese, iron,cobalt, nickel, ruthenium, palladium, platinum and cerium.

Depending on the reactions in'which the contact mass is to be used, theexchangeable bases introduced may be specific catalysts, they may bestabilizers, or the may be stabilizer promoters. They may e introducedas simple ions or as complex ions, and may enhance the catalyticactivity of the final contact mass, improve its physical structure, orboth. It should be understood that while the present invention does notinclude hydrogenations in which permutogenetic contact masses are usedcontaining exchangeable bases as their only specific catalysts certaincatalytically active elements such as, for example, some of thoseenumerated in a foregoing paragraph, may be introduced by base exchangeinto contact masses which already contain specific catalytically activecompoexchange, troduced singly change" are the gold, ammonia,

in the non-exchangeable nucleus of the base exchange molecule orchemically united therewith in the form of anions to produce salt-likebodies or imbedded therein in the form of diluentsu As has beendescribed above, base exchange bodies can be caused to react with comounds forming therewith salt-like bodies. The radicals maybe present inthe form of simple acid radicals, polyacid radicals or complex acidradicals, and include radicals containin the following elements:--chromium, vana um,

tungsten, uranium, molybdenum, manganese, tantalum, niobium, antimonyselenium, tellurium, phosphorus, bismuth, tin, chlorine, platinum,boron. Among the complex radicals are ferro and ferricyanogen, certainammonia complexes and the like. The amount of acid radicals caused tounite with the base exchange bodies to form salt-like bodies may bevaried so thatthe resulting products may possess the character of acid,neutral or basic salts. Most of these acid radicals are stabilizers orstabilizer promoters for the catalytic hydrogenation of non-nitrogenouscompounds. Y

' bodies,

ascenae The base exchange bodies .diluted or undiluted, or some of theirsalt like body derivatives, may be treated with acids such as mineralacids, for example, 240% sulfuric, hydrochloric or nitric acids, toremove part or all of the exchangeable bases, or also part or all of thebasic portion of the nucleus.

In the case of zeolites, the partial leaching with acid, which leavespart or all of the basic portion of the nucleus or even part of theexchangeable bases, does not affect the function of the zeolites ascatalysts when they contain catalytically active elements in the basicportion of the nucleus, or in some cases even exchangeable bases, andsuch partially leached catalysts are of great importance in manyreactions. Where the leaching is carried out to completion the advantageous physical structure remains to a considerable extent the same,but the remainder is of course a form of silica, or in the case ofzeolites in which part of the silica is replaced b other acidiccompounds, a mixture of the t o, and usually will not be a specificcatalyst for the hydrogenation of non-nitrogenous organic compounds. Itserves, however, as an advantageous physical carrier of specificcatalysts, and in the case of partially substituted zeolites may alsocontain stabilizer promoters.

Leached non-silicious base exchange either partially or completelyleached, may contain catalytically active components and behave ascatalyst, stabilizer promotors or both, and many important catalysts forthe hydrogenation of nonnitrogenous organic compounds are thus obtained.This is particularly the case for reactions where a relativelyalkali-free contact mass is required for best results and where v thealkaline content of a contact mass containing a base exchange body maybe too great for optimum results.

Base exchange bodies or their derivatives, diluted or undiluted, mayalso be coated in the form of films on massive carrier granules or maybe impregnated therein. Themassive carriers may be inert, activating, orthemselves catalysts. For example, certain catalytic metal alloys,minerals, especially Aluminum or copper alloy granules perform anadditional advantageous function in that their relatively high heatconductivity tends to prevent local overheating in highly exothermichydrogenations of nonnitrogenous organic compounds which isofconsiderable importance in obtaining good yields, as many of thereactions, particularly hydrogenations, are equilibrium reactions, andat higher temperatures hydrogenation catalysts reverse their functionand tend to favor, dehydrogenation with resultcopper minerals, fallwithin this class.

emma ing lowering of yields and contamination of the product.

Example 1 Four solutions are prepared, as follows: 1. 27 parts of freshlprecipitated chromium hydroxide in the orm of a suspension,

as obtained by precipitation from the corresponding chromous saltsolution, are treated with sufficient 2 N. sodium hydroxide solution totransform them into the corresponding sodium chromite.

2. 8 parts of cadmium nitrate with 4 mols of water are dissolved in 50parts of water and sufiicient 2 N. sodium hydroxide solution is addeduntil the corresponding sodium cadmiate solution is obtained.

3. 4 parts of V 0 freshly prepared by reducing a corresponding amount ofV 0 are dissolved in 5 N. sodium hydroxide solution- 'to the coffeebrown sodium vanadite.

4. 50 parts of nickel nitrate are dissolved in 250 parts of water.

Solutions 1, 2 and 3 are mixed together, and 30 parts of colloidal SiOkieselguhr or finely pulverized activated carbon, or a mixture, areadded as diluents and thoroughly mixed. The nickel nitrate mixture isadded to the mixed metallates with vigorous agitation until the reactionproduct obtained is slightly alkaline or neutral to phenolphthalein. Inany event strong alkalinity to litmus must be maintained. The reactionproduct is then freed from the mother liquor without washing theconstituents and the non-silicious base exchange body "containschromium, cadmium, vanadium and nickel in non-exchangeable form dilutedwith the finely divided silicious material, or activated carbon. Thebase exchange body is preferably hydrated with water by trickling thelatter over the crushed base exchange fragments, and then dried,whereupon it is reduced with hydrogen-containing gas at temperaturesfrom 250 to 350 C.

The contact mass prepared as described above is very eifective for thecatalytic hydrogenation of esters of unsaturated acids, such as, forexample, the esters of maleic and fumaric acids to esters of succinicacid, esters of acrylic acid to esters of propionic acid, and the like.The hydrogenaton should take place in the presence ofhydrogen-containing gases, using either the theoretical amount or,preferably, an excess, and may be carried out either in the vapor phaseor in the liquid phase, with or without pressure at ordinary or elevatedtemperatures.

As an example of these reactions dimethyl maleate, having a boilingpoint of 205 0., with or without admixture of dimethyl fumarate with aboiling point of 192 C., is vaporized with a more or less great excessof hydrogen and passed over the contact mass at, 170-190 0., preferablyin a converter such as a converter provided with automatic doublecountercurrent heat exchange. The corresponding dimeth l ester ofsuccmic acid is obtained and, if desired, may be saponified to producesuccinic acid of high purity.

Under the same reaction conditions free maleic acid can also behydrogenated to sue cinic acid with an excess of hydrogen, but where anyconsiderable amount of fumaric acid is present the latter isnotsnfiiciently volatile to get into the gas stream, and it is,therefore, preferable in most cases to hydrogenate theesters.

The same contact .mass may-be used for hydrogenating these esters oracids in the liquid phase. Instead of using the acids, however, whichwould strongly corrode the reaction vessel, the alkali metal saltssuchas the sodium salts, may be used in aqueous solution, the catalyst ofcourse being suspended as in all liquid phase reactions. While theprocess can-be carried out at room temperature, it is preferable to usea somewhat elevated temperature. Instead of using the concentratedesters, they may be dilutedwith indifferent solvents such as alcohols,acetone, cyclohexane, cyclohexanol, and the like. It is also possible toemulsify the esters with water, but very vigorous agitation must bemaintained in order to keep a good emulsion.

The contact mass may be further modified by introducing copper throughbase ex-' leaching the base exchange catalystwith dilute acid to leachout the exchangeable alkali present, thedesirable physical structure ofthe contact mass being retained. The leached product should be reducedat 300- 400 0., and can then be effectively used for the hydrogenationof unsaturated esters, for example crotonyl esters may be reduced withgases containing hydrogen in the theoretical amount or in small excess,the mixture being passed over the contact mass at 120140 C and producingbutyl esters as the main product.

- Ewample'f? 50 parts of kieselguhr are suspended in 300 parts of waterand 50 parts of concentrated hydrochloric acid are poured in and thewhole is heated up to 60-70 C. with vigorous agitation. The kieselguhris then filtered off and washed with distilled water until entirely freefrom acid and the purified product is suspended in a nickel nitratesolution containing 180 parts of nickel nitrate with 6 mols of water in500 c. c. of water. Nickel hydroxide is then precipitated in a finestate of division in the kleselguhr using 2 N. sodium hydroxidesolution, whereupon the mass is filtered and carefully washed withdistilled water until free from sodium nitrate.

24 parts of SiO in the form of a commercial sodium waterglass solution,as free from iron as possible, are diluted with 250 parts of water andthe kieselguhr impregnated with nickel hydroxide is suspended thereinwith vigorous agitation.

8 parts of A1 0 in the form of the hydroxide freshly precipitated from asalt solution with ammonia are treated with 2 N. sodium hydroxidesolution until all of the aluminium oxide goes into the solution assodium aluminate. This solution is then poured into the waterglasssuspension with vigorous agitation and heated to 50-60 C. resulting inthe precipitation of an aluminum zeolite containing nickel hydroxide andkieselguhr as diluents. The yield of the zeolite may be increased byneutralizing any excess of alkali with dilute nitric acid. The zeoliteis then sucked from the mother liquor, washed with 500 parts of water insmall portions and dried preferably at temperatures below 100 C.

After drying the zeolite is hydrated with water in the usual manner,again dried and pulverized and then treated with hydrogencontaininggases. After this preliminary treatment the contact mass is well suitedfor the reduction of unsaturated esters. The effectiveness of thezeolite contact mass may also be enhanced by the introduction ofmagnesium oxide or oxides of the rare earth metals by base exchange.Another modification consists in leaching the zeolite with dilute acidsremoving part or all of the exchangeable alkali. The leaching may beeffected by treating the zeolite after hydration with 13% nitric aciduntil the desired amount of alkali has been removed. The amount ofnitric acid necessary can be readily determined by testing a sample ofthe zeolite.

Instead of using an aluminate as the metallate component of the contactmass, other metallates may be substituted, for example beryllate mayreplace part or all of the aluminate. Other metal oxides can beintroduced by base exchange and may possess specific catalyticproperties or be stabilizer promoters.

Where a high concentration of catalytically effective metal oxides,suchas nickel oxide, are present, either as diluents or embedded in thezeolite molecule, it issometimes of advanta e to treat the contact masswith compoun s containing the acid radicals of the metal acids of the5th and 6th groups of the periodic system in order to form theso-calledsalt-like bodies, thus, for example the diluted zeolite prepared asdescribed above may be treated with 3-5% of nickel nitrate solutionuntil a maximum of base exchange has taken place. After washing out theexcess nickel nitrate the wet zeolite is treated with 500 parts of 1%ammonium vanadate solution, the solution being permitted to trickle overthe zeolite on a filter. The resulting product is a salt-like body andis a well stabilized contact mass for the reduction of unsaturatedesters.

Of course other nickel containing contact masses described in theforegoing examples may also be used for reduction of unsaturated esters.

Other hydrogenations may be effected by means of the same contact mass.Thus, for example, esters of phthalic acid, such as thmethyl, dibutyl,or diamyl phthalates can be hydrogenated to the corresponding esters ofhexahydrophthalic acid. Similarly, esters of benzoic or toluic acid canbe hydrogenated to the corresponding hexahydro derivatives. Terpenes canalso be hydrogenated at 180 200 C. in the vapor phase with an excess ofhydrogen.

In the claims the term permutogenetic covers base exchange bodies,silicious or nonsilicious, the products obtained by the acid leaching ofthese base exchange bodies and the salt-like bodies obtained by thereaction of these base exchange bodies with compounds the acid radicalsof which are capable of reacting with the base exchange bodies toproduce products which show most of the properties of salts. When soused in the claims,

the term permutogenetic will have no other meaning.

This case is a division of my pending application Serial No. 256,917filed February 25, 1928.

What is claimed as new is:

1. A method of catalytically hydrogenating esters of nitrogen-freeunsaturated acids, which comprises causing them to react with hydrogencontaining gases in the presence of a contact mass containing apermutogenetic body, at least one catalytically effective componentbeing other than an exchangeable ase.

2. A method of catalytically hydrogenating esters of nitrogen-freeunsaturated acids. which comprises vaporizing them, mixing the vaporwith hydrogen containing gases. and passing the mixture at a reactiontemperature over a contact mass containing a permutogenetic body, atleast one catalytically effective component being other than anexchangeable base.

3. A method of catalytically hydrogenating esters of nitrogen-freeunsaturated acids,

which comprises subjecting them to reaction with hydrogen containinggases in the presence of a contact mass containing a permutogenetic bodyhaving at least one catalytically effective component other than anexchangeable base and also containing at least one substance includedwithin the group consisting of dehydrogenation catalysts, oxidationcatalysts, splitting catalysts, and condensation catalysts.

4. A method of catalytically hydrogenating esters of nitrogen-freeunsaturated acids, which comprises subjecting them to reaction withhydrogen containing gases in the presence of a contact mass containing apermutogenetic body having at least one catalytically efl ectivecomponent other than an exchangeable base and containing at least onecompoundof an element included in the group metals and rare earth metalswhose oxides are not reducible by hydrogen and at least one substanceincluded within the group consisting of dehydrogenation catalysts,oxidation catalysts, splitting catalysts, and condensation catalysts.

5. A method of catalytically hydrogenating esters of nitrogen-freeunsaturated acids, which comprises causing them to react with hydrogencontaining gases in the presence of a contact mass containing apermutogenetic body, at least a portion of the catalytically effectivecomponents being chemically combined in non-exchangeable form in or withthe .permutogenetic body.

6. A method of catalytically hydrogenating esters of nitrogen-freeunsaturated acids, which comprises causing them to react with hydrogencontaining I gases in the presence of a contact mass containing adiluted permutogenetic body.

7. 'A method according to claim 6, in which at least a portion of thecatalytically effective components are present in the form of diluentsin the permutogenetic body.

8. A method according to claim 6, in which the diluted permutogenetiobody contains at least one substance included within the groupconsisting of dehydrogenation catalysts, oxidation catalysts, splittingcatalysts, and condensation catalysts.

9. A method according to claim 6, in which the diluted permutogeneticbody contains at least one compound of an element included in the groupconsisting of alkali metals, alkaline earth metals, and rare earthmetals whose oxides are not reducible by hydrogen.

10. A method according to claim 6, in which the diluted permutogeneticbody contains at least one compound of an element included in the groupconsisting of alkali metals, alkaline earth metals, and rare earthmetals whose oxides are not reducible by hydrogen, and at east onesubstance included within the group consisting of dehydrogenationcatalysts, oxidation catalysts, splitting catalysts, and condensationcatalysts.

of a contact mass containing a permutogenetic body, at least onecatalytically effective lc)omponent being other than an exchangeablease.

12. A method of catalytically hydrogenating esters of non-nitrogeneousunsaturated aliphatic acids, which comprises causing them to reactvwithhydrogen containing gases in the presence of a contact mass containing adiluted permutogenetic body.

13. A method of catalytically hydrogenating esters of maleic acid toesters of succinic acid, which comprises causing them to react withhydrogen containing gases in the presence ofa contact mass containing apermutogenetic body, at least one catalytically effective componentbeing other than an exchangeable base.

14. A method of catalytically hydrogenating esters of maleic acid toesters of succinic acid, which comprises causing them to react withhydrogen containing gases in the presence of a contact mass containing adiluted permutogenetic body.

15. Method accor ing to claim 13, in which the esters are vaporized bymeans of gases containing hydrogen and the reaction is ef-- fected inthe vapor phase.

16. Method according to claim 14, in which the esters are vaporized bymeans of gases containing hydrogen and the reaction is effected in thevapor phase.

Signed. at Pittsburgh, Pennsylvania, this 20th day of September, 1929.

ALPHONS O. J AEGER.

11. A method of hydrogenating esters of i nitrogen-free, unsaturatedaliphatic acids, which comprises causing them to react with hydrogencontaining gases in the presence

